Scales are made with different divisions for different purposes. For machine, structural and architectural…

Illustration of equal circles to show that two central angles have the same ratio as their intercepted…

Illustration of 2 narrow right circular cylinders with equal heights (thickness) and different diameters.…

Illustration of 2 right circular cylinders in which one cylinder is twice the height of the other.

Illustration of 2 right circular cylinders in which one cylinder is twice the height and twice the diameter…

Illustration of an extension ladder. If ladder is leaned against a building, it will form a right triangle…

Illustration of a ladder that is not perpendicular to the ground. If it is set on the ground and leaned…

Illustration of a ladder that is not perpendicular to the ground. If it is set on the ground and leaned…

Illustration of a ladder that is not perpendicular to the ground. If it is set on the ground and leaned…

Illustration of a ladder leaning against the side of a building (wall) to form a right triangle .

Illustration of a ladder leaning against a palm tree, that is perpendicular to the ground, to form a…

Illustration of a ladder leaning against a palm tree, that is perpendicular to the ground, to form a…

Illustration of a ladder leaning against a palm tree, that is perpendicular to the ground, to form a…

Illustration of 2 ladders leaning against opposite sides of a palm tree to form similar right triangles.…

Illustration of 3 ladders leaning against the side of a building (wall) to form right triangles. The…

Illustration of a lever with fulcrum F. W represents the weight lifted, P is the force that does the…

An illustration of a lever with weights m and n with distances a and b from fulcrum. Illustration could…

Illustration of an ordinary steel-yard being used as a lever. F represents the fulcrum. Weight P is…

Illustration that shows if two parallel lines are cut by three or more transversals that pass through…

Illustration that shows if two parallel lines are cut by three or more transversals that pass through…

Diagram used to prove the theorem: "If a pyramid is cut by a plane parallel to the base, the edges are…

"If two straight lines are cut by three parallel planes, the corresponding segments are proportional."

Illustration that shows similar polygons (pentagons) that can be used to show proportionality.

Illustration that shows similar polygons (pentagons) that can be used to show proportionality.

Two similar polyhedrons may be decomposed into the same number of tetrahedrons similar, each to each,…

Illustration of a hydraulic machine. "A principle known as Pascal's Law states that pressure exerted…

Illustration of 2 right rectangular prisms. The bases are congruent, but the height of the smaller prism…

Illustration of 2 right rectangular prisms. The bases are congruent, but the height of the smaller prism…

Illustration to show that an angle bisector of a triangle divides the opposite side into segments which…

Illustration to show that a bisector of a an exterior angle of a triangle divides the opposite side…

Illustration to show that if parallel lines are cut by any number of parallels, the corresponding intercepts…

Illustration to show that if a line is drawn through two sides of a triangle parallel to the third side,…

Illustration to show that if a line divides two sides of a triangle proportionally, it is parallel to…

Illustration used to construct a square that shall be in proportion to a given square.

Illustration used to construct a square that shall be in proportion to a given square.

The volumes of two similar tetrahedrons are to each other as the cubes of their homologous (corresponding)…

Diagram used to prove the theorem: "Two tetrahedrons having a trihedral angle in each equal, are to…

Illustration of a leaning tower with a perpendicular drawn from the top of the tower to the ground to…

Illustration of a palm tree that is perpendicular to the ground. The tree is perfectly straight, as…

Triangle diagram for measuring heights of trees using proportions.

Triangle diagram for measuring heights of trees using proportions

Right triangle inscribed in semicircle. Illustration shows that the perpendicular from any point in…

Illustration of oblique triangle used to find distance across a river.

Illustration of oblique triangle used to find distance across a river.

Illustration of oblique triangle used to find distance across a lake.

Illustration that shows two mutually equiangular triangles are similar.

Illustration that shows that two triangles which have their sides respectively parallel, or respectively…